1. Field of the Invention
This invention relates to a conveying apparatus and a conveying system in which a plurality of feed portions are arranged two-dimensionally in a distributed manner over a conveying surface, and the feed portions sequentially feed an article so as to move the same to a predetermined position on the conveying surface.
2. Related Art
FIG. 22 shows a feed portion 1 provided in a conventional conveying apparatus of the type described. In this feed portion 1, a rotation shaft 3 is provided within a twist gear 2 rotatable about a vertical axis, and a feed roller 4 and an output bevel gear 5 are fixedly mounted on the rotation shaft 3. An input bevel gear 6 in mesh with a lower side of the output bevel gear 5 is driven by a servomotor so as to rotate the feed roller 4, while a spur gear 7 in mesh with the outer periphery of the twist gear 2 is driven by a servomotor so as to rotate the twist gear 2 (see Patent literature 1; JP-A-6-298321). With this construction, an article is conveyed in an arbitrary direction on a conveying surface of the conveying apparatus.
In the above conventional conveying apparatus, however, the roller 4 is provided within the twist gear 2, and therefore the shapes of the twist gear 2 and feed roller 4 are limited, so that the following problems have been encountered. Namely, it is difficult to form the twist gear 2 into a compact design since this twist gear receives the feed roller 4 therein, and the interval between the adjacent feed portions 1 and 1 becomes large. And besides, it is difficult to form the feed roller 4 into a large size since this feed roller 4 must be received within the twist gear 2, and the area of contact of the feed roller 4 with the article can not be increased, so that a force can not be efficiently transmitted from the feed roller 4 to the article. Because of these factors, it has actually been difficult for the conventional conveying apparatus to feed the article in an arbitrary direction on the conveying surface.